Guard device for lock mechanism



N J. REssETAR April 6, 1948. 2,439,099

GUARD DEVICE FOR LOCK MECHANISM Filed Nov. 1e, 1945 Hl .3g l iff/16 hl. l

.v l! I ii i'l lijf-M Patented Apr. 6, 1948 UNITED STATES PATENT OFFICE` GUARD DEVICE FOR LOCK MECHANISM Nicholas J. Ressetar, Oneida, N. Y.

Application November 16, 1945, Serial No. 629,101

(Cl. Y-364) 4 Claims.

This invention pertains generally to a guard device for lock mechanisms and more particularly to a magazine 'structure for feeding the key to a lock such as, for example, the familiar forms of tumbier locks. l

It is the principal purpose of this invention to provide a guard for a lock mechanism of such character that the lock cannot be tampered with and can only be operatedy by means of a proper key that is fed into the mechanism by a magazine.

Another object of the invention resides in the provision of a bolt form of magazine shaped or otherwise recessed to receive `the cam portion of a key and permanently associated with the keyway of a lock. Other details of the invention and features of improvement will be apparent from the following description of a preferred embodiment taken in connection with the accompanying drawings, in which:

Fig. 1 is a perspective View in front elevation of a lock embodying the guard device;

Fig. 2 is a phantom s ide elevation partly in section showing the guard device in a different position relative to the lock;

Fig. 3 is a cross-sectional View taken along the line III- III of Fig. 2; and

Fig. 4 is a side elevation similar to Fig. 2 but showing the guard device in withdrawn position.

In the drawings reference numeral lil indi- Cates a lock such, for example, as the conventional form of tumbler or more specifically, a cylinder tumbler lock. At the end where the key would ordinarily be inserted, the lock I0 is provided with a magazine I2 having Ithe shape of a bolt and receiving the cam portion of a key I 4, the turning head of this key being omitted for reasons that will be set forth.

As seen best in Fig. 2, the magazine I2 is formed with a longitudinal slot IB in which the key or key portion Ifl iits snugly. A transverse recess I6 is cut in the bolt I2 adjacent the end of slot I8 to permit the key portion I4 to be grasped by the lingers for ready insertion or removal.

It will be observed in Fig. 4 that the lock Iii includes as part of the keyway a longitudinal bore or lock chamber 2%0 which receives the magazine bolt I2 when it is pushed home by means of a knurled head formation or knob 22 adapted to engage the adjacent front portion of the lock I@ as a stop.

In Figs. 2 and 4 a conventional set of springpressed tumblers are indicated generally at 24, and it will be understood that when the key lil is in the position of Fig. 2 these tumblers 24 will and abut a stop shoulder 28 formed within the` lock I@ so as to prevent withdrawal of the magazine I2 beyond a position in which the key I4 may be inserted, after the manner illustrated in Fig. 4. As it is likely that dust and other debris will accumulate inthe slot I6 upon continued use of the lock. a clean-out hole 39 of generous proportions is provided in the bottom of this, slot so that lint, dirt and the like` Will either fall out immediately or be readily removable.

vIt Will thus be seen that the guard-device of this invention presents a number of novel advantages and particular utility. Without material alteration of conventional lock structure and with a minimum of added and inconspicuous structure, operation of a lock so equipped by means of a skeleton key is prevented.

The construction of the magazine l2 is such that no matter what the position of the magazine is, it is impossible to insert a wire or pick to reach all of the tumblers. At least two of the tumblers remain completely covered by the solid portion of the magazine at all times. This is apparent from the construction as better shown in Figs. 2 and 4 of the drawing in which the length of the magazine bolt from the knurled head 22 to the slot I is at least equal to one-half the length of the slot. Damage to the lock by such tampering or picking is thereby avoided. No material change in the form of key is required but only removal of the head portion. The slotted magazine bolt is adapted to receive any key of the type indicated so that it is applicable to a whole series of locks irrespective of the tumbler arrangement for which the individual key provides the necessary accommodation. The knob 22, in addition to providing convenient means for inserting and withdrawing the magazine and turning the key when in operative position, also acts as a cover vfor the bore and thereby prevents undesired entry of dirt or moisture. Projection 2li and stop shoulder 28 constitute prefered means for preventing removal of the magazine I2 after assembly in the lock mechanism Ill.

From the foregoing description and the illustrative showing of this invention it will be apparent that the device is simple, rugged, dependable, and inexpensive to manufacture.

Since it will be obvious that changes can be made in the details of construction and arrangement of parts Without departing from the prin ciples of this invention, it is not intended that the scope thereof shall be limited other than as may be required by the appended claims.

Having thus described my invention, what I claim as novel and desire to secure by Letters Patent of the United States is:

1. In combination with a, tumbler lock having a keyway formed therein, a cylindrical bolt magazine slidable and rotatable in the keyway of the lock, said magazine being provided with a stop formation arranged adjacent its inner end to engage a portion of the lock and prevent removal of the magazine from said keyway, and said magazine being longitudinally slotted intermediate its outer end and said stop formation to receive and retain the cam portion of a key for said lock in a position to cooperate with a locking mechanism of said lock when the magazine is home.

2. In combination with a cylinder tumbler lock having a keyway bore formed therein, a cylindrical bolt magazine complemental to and slidable in said keyway, said magazine being provided with a knurled head on its outer end engaging the lock land covering the keyway bore when the magazine is inserted and a lateral projection adjacent its inner end arranged to prevent removal of the magazine from said keyway, and said magazine having a. slot intermediate its ends, and theV cam portion of a key for said lock retained in the slot of said magazine, said magazine having one end of its slot recessed transversely to facilitate removal of the cam portion of a key and the slot being arranged longitudinally of the bolt magazine to cause the cam portion of the key to cooperate With the tumbler mechanism of said lock when the magazine is home.

3. In combination with a cylinder tumbler lock having a keyway formed therein, a cylindrical said magazine being provided with a projection arranged to engage the interior of the lock to prevent removal of the magazine from said key- Way, said magazine being provided also with a head on its outer end, and said magazine having a longitudinal key slot intermediate its ends, said slot positioned at least one-half its length from said magazine head so that at no time can all of the tumblers be reached by means of a pick or Wire, and the cam portion of a key for said lock received in the slot of said magazine to cooperate with the tumbler mechanism of the lock when the magazine is home,

4. In combination With'a cylinder tumbler lock having a keyway formed therein, a cylindrical bolt magazine slidable in the keyway of the lock, said magazine being provided with a projection arranged to engage the lock to preventiremoval of the magazine from said keyway, said magazine having a longitudinal slot intermediate its ends, said slot having an opening form-ed therein and 'extending through to the underside of said magazine to prevent clogging and to facilitate cleaning of the slot, and the cam portion of a key for said lock disposed loose in the slot of said magazine to cooperate with the tumbler mechanism of the lock when the magazine is home.

NICHOLAS J. RESSETAR.

REFERENCES CITED The following references are of record in the nie of this patent:

UNITED STATES PATENTS 

